10 Questions About Crust You Should Know

CRUST implements the incentive layer protocol for decentralized storage. It is adaptable to multiple storage layer protocols such as IPFS, and provides support for the application layer. Crust’s architecture also has the capability of supporting a decentralized computing layer and building a decentralized cloud ecosystem.

01. What is Crust?

Crust is an application-type public chain that motivates decentralized cloud services. At this stage, Crust will first implement a decentralized storage layer, and then upgrade to a computing layer that supports decentralization.

And what exactly is Crust? Briefly, Crust currently focuses on solving three problems involved in the hierarchical and modular that can be refined into three keywords: report, packaging, and services.

Report, refers to reporting storage workload happened on statistical nodes to the on-chain. To solve the problem of workload reporting of the node, Crust based on the TEE’s trusted execution environment technology, proposed MPoW (meaningful proof of work) which means a meaningful workload proof mechanism.

The Crust storage node will report periodically to the whole network how much storage space “I” provides, which user files “I” stores, and so on. With the help of the MPOW mechanism, the workload in the report is verifiable and credible;

Packaging refers to recording and packaging workload reports with other transactions into blocks. Crust team designed a PoS consensus algorithm that defines the amount by storage resources, called GPoS (Guaranteed Proof of Stake).

Through the workload report provided by the first layer MPoW mechanism, the storage workload of all nodes can be obtained on the Crust, and the GPoS algorithm of the second layer is to calculate the Staking quota for each node according to the workload of the node. According to this quota, then it carries on the PoS consensus.

Service is a user-oriented storage service. In a word, how to bring high-quality decentralized storage services to end-users, with which you can compare the common cloud services, such as cloud disks to the customers and iCloud, and Ali Cloud and Amazon cloud to the business.

The purpose of Crust decentralized cloud is to motivate nodes to provide decentralized storage and computing capability to data through blockchain technology. Finally, it embodies the universe decentralization of data storage and computing power.

02. Under what scenarios can Crust be used?

Crust decentralized storage layer provides a distributed file system. Meanwhile, Crust also provides some encapsulated standard interfaces such as Amazon S3-like systems. Any application scenarios involving data storage, such as cloud services, edge computing, and decentralized applications all belong to Crust’s appropriate scenarios.

Especially in the edge computing scenario, compared with the centralized cloud storage, the Crust decentralized storage is closer to the edge side, which can achieve a relatively low cost and high-performance result.

03. What is TEE and what is the role of TEE in Crust?

TEE is the abbreviation of Trusted Execution Environment, a secure area on the main processor that guarantees the security, confidentiality, and integrity of code and data loaded into the internal environment.

TEE, the trusted execution environment technology, whose essence is to provide a safe space to secure data and code execution. The code and data in this space, are free from the influence of conventional operating systems, and can effectively ensure data confidentiality and integrity.

TEE act like an honest supervisor in the Crust. Periodically check on whether the node is working properly, or whether there is a wrong recording or missing user data. this is what we call the Crust MPoW mechanism.

At the same time, TEE also play the function of “safe box”. For users’ sensitive data, TEE encryption denies storage nodes to read user privacy themselves. It’s like a vault tenant can’ t open a client’s vault.

04. How does Crust protect the privacy of enterprise data?

Crust can be responsible for data storage, and cloud storage of private data will also become a new breakthrough.

The enterprise can directly use the Crust cloud disk, or become compatible with Crust SDK (S3-like interface) on the enterprise data platform.

SDK will encapsulate node selection, redundant backup, retrieval acceleration, metadata management and other functions, and enterprises only need to simply setup according to business needs. If privacy is configured, access to privacy data will be encrypted throughout the whole procedures, which will enable more enterprises to upload business data to the clouds.

05. What are the relationships and differences between Crust and IPFS?

The relationship between Crust and IPFS is quite similar to the relationship between incentive layer and storage layer. Filecoin protocols encourage nodes in the network to provide storage capacity through incentives, which IPFS can exactly provide this kind of storage ability.

The following is a comparison of the relationship and differences between Filecoin and Crust in the decentralized storage incentive layer.

At this stage, there are two key problems in the incentive layer of decentralized storage: proof and incentive. Proof mainly refers to how to correctly reflect the off-chain storage state to the on-chain, and incentive is the incentive plan for the storage node, that is, the way the node obtains the rewards.

The methods and technical paths used to solve these two problems in Crust and Filecoin are very different.

In terms of the Proof, The realization of Filecoin PoR, Proof of Replication and PoSt, Space-time proof is the most expected. The sophisticated zero knowledge proof and VDF algorithms are very novel techniques in the Filecoin technical path.

Nevertheless, from the view of the data of Filecoin testnet, a large number of complex proof algorithms bring huge computing cost, such as storage nodes demanding 128G of memory with matched GPU to prove the calculation. Compared to Crust, it designed meaningful workload proof (MPoW) by introducing TEE technology.

The MPoW proof process can be very simple and efficient, and many PCs available to support TEE. That is to say, to solve the same proof problem, the cost and threshold of Crust are lower, which is a different idea to solve the proof.

Next Let’s talk about incentives. At the early stage, the node incentive of Filecoin and Crust mainly comes from block rewards, but the difference is that in Filecoin current economic model, the block rewards of Filecoin is assigned to the block node, and the probability of generating blocks is proportional to the workload of the node. Its core is PoW Base model with more work and more gain.

However, the Crust GPoS mechanism, whose the block reward is proportional to the staking amount of each node, and the upper limit of the staking amount of each node is limited by the storage amount provided by the node. So the essence of GPoS is based on PoS. This is also a reference to the Polkadot NPoS model for innovation and design.

Meanwhile, because the acceptable staking amount of nodes is limited by the amount of storage, GPoS can avoid the centralization concerns of PoS.

06. What are Crust consensus mechanism and economic model?

The Crust uses the GPoS (Guaranteed Proof of Stake) consensus, known as a PoS consensus on that storage resources as guarantee amount.

Similar to the existed PoS projects, the node needs to stake the CRU token to compete for the right to generate blocks, what is different is that the node also needs to provide storage resources to obtain the corresponding amount of guarantee, in other words, you can only stake the corresponding amount of CRU when you have the amount of guarantee.

Under this mechanism, it is necessary to have both two kinds of assets, storage resources and CRU token of becoming nodes with combining the advantages of resource-type (such as bitcoin) and tokens-type (such as Cosmos) consensus mechanism to ensure network security more effectively.

If hacker want to attack Crust network by consensus, in addition to having a large proportion of CRU token, also require to be able to control enough storage resources. With such a design it will make the attack very difficult.

On the premise that a node has storage resource guarantee, it can also seek a guarantor to use CRU to guarantee for it. That is, the CRU staked on the node can be self-owned or from the guarantor. When the guarantor chooses to guarantee the node, besides the income, he also required to bear the risk of node punishment.

If the node is fined by the system for triggering the penalty mechanism, the guarantor will also be fined according to the ratio of the guaranteed asset. Under this mechanism, guarantors tend to choose to guarantee nodes with good faith and high-quality service, and a balance between guarantee income and penalty risk will be determined by the market.

As a network protocol of underlying data storage, Crust provides the function of storing resource transaction, and CRU token is used as the guarantee of transaction contract in this trading market to ensure the order of transaction market.

Lastly, similar to other blockchain projects, CRU token will also be used as a network transaction fee, similar to the Gas in Ethereum. It can also be used directly to purchase resource services in the network.

07. How to cooperate with token progress and ecological development?

After full discussion with many parties, the Crust token model is designed. At present, the complete economic model has not been released. But here I will introduce it to you in advance:

The original token in the Crust network mainly has the 6 significant functions:

1. Used for staking, to maintain GPoS consensus of the network
2. Used to guarantee the selected nodes
3. As a contract guarantee and commission for the provision of resource services
4. As a transaction fee for the use of the network
5. Can be used to purchase resource services
6. Campaigns and ballots for on-chain governance mechanisms, and voting on the proposal.

The value of tokens is closely related to the size of the Crust network, and when the Crust network is used by a large number of users, the demand of CRU will rise accordingly.

In the token allocation scheme of Crust, 60% of the token will allocate to the “mining” work of the resource node after going online. About 16% will be sent to fans and community of the project and about 8% will be used to incubate ecological applications. The rest will be transferred to some early investors and project teams.

At present, the long-term inflation rate of Crust tokens is set at 1.8%, and through the burning mechanism of transaction fees, the inflation rate of tokens is extremely low, and even possibly deflation may happen.

Crust tokens and ecology are closely combined, tokens benefit from ecological development, but the market does not affect the development of the project. Our service market transactions, for example, can accept user-friendly pricing coins such as stable coins, and transaction fees are similar to ETH Gas mechanisms. Ecological applications are all priced by the the market, follow the market mechanism.

08. Why did Crust choose Substrate?

First, the Substrate technical framework is excellent and friendly supportive to the performance and functions of the application type blockchain, like Crust. For example, the BABE/GRANDPA algorithm plays a key role in the implementation of the GPoS consensus protocol. Offchain Worker also supports the implementation of the Crust storage market.

Second, because Crust storage workload consensus is based on TEE technologies, and TEE technologies have a variety of solutions, such as IntelSGX, AMD SEV and ARM Trustzone. Crust autonomous mechanism based on Substrate can be used to maintain TEE solutions list.

Finally, XCMP protocol brings the possibility for Crust cross-chain ecology. Let’s think of the storage services that Crust provides in the future, which can be purchased in a variety of Token, and any project in the ecology can use the storage capacity brought by the Crust. So this is a combination of 1+1 greater than 2.

09 How does Crust join in Web 3/Polkadot ecology and what will be the impact?

The location of the Crust in the Web3 protocol stack belongs to the “Data Distribution Protocols” from the views of functions and techniques, and Crust storage layer protocol will provide the encrypted storage required by the upper layer protocol and the support of large computation.

The upper design of the Crust includes storage market, retrieval market, file management and other mechanisms, which naturally needs to be compatible with some decentralized data transmission protocols, applications and financial systems, which have been fully implemented in Web3 ecology.

Some Web3 ecological file protocols, such as DAT and Shift, can provide flexible file management functions and better support version control of dynamic files, but all need a storage incentive layer, such as Crust to provide the most basic storage resources.

Finally, Crust project has been added to the Polkadot ecology to effectively support the projects and applications in the ecology. Since Crust, IPFS and Phala projects are closely combined technically, Crust can also effectively expand the Web3 technology ecology.

10. Recent developments and future plans

In March 2020, we launched the Crust Development Testnet, at the same time we open-sourced some source code. Crust successively joined Substrate Builders Program, Web3.0 Bootcamp, and received grant from the Web3 Foundation. Crust expect that the construction of distributed cloud ecology can be realized through closer cooperation.

This July we launched Crust Public Testnet, in which version Crust will support full-featured economic models and storage trading markets, and plan to join hands with Phala Testnet to provide a decentralized storage for Web3 applications.

The Mainnet of Crust is expected to be launched by the end of 2020 and meanwhile access Polkadot slots.